[BUGFIX] Wrong height for .t3-row-header

Also compress the final CSS files.

Releases: 2.0.0
Change-Id: I7fa2d1715f2018bc0fd8399e46945d935a53dd10
Reviewed-on: http://review.typo3.org/32100
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>